Helen Fisher

Any kind of novelty or excitement drives up dopamine in the brain, and dopamine is associated with romantic love.

When you massage someone, the levels of oxytocin go up in the brain, and oxytocin is one of the chemicals that drives attachment.

Men have a psychological need to show off their courage and strength. When he sees you talking to another guy, that instinct kicks in and he jumps to protect you and prove he's worthy of your love.

My first career ambitions involved turning into a boy; I intended to be either a railway guard or a knight errant.

Technology is characterized by constant change, rapid innovation, creative destruction, and revolutionary products.

Well, I actually wrote her a letter a couple of days ago congratulating her. The tone I tried to convey in the letter is, look, you are a part of a great American historical process.